The correct answer is option 4, Vairengte. The Indian Army`s counter-insurgency school is located in Vairengte.
Option 1, Ranker, is not the correct answer as there is no mention of a counter-insurgency school in Ranker.
Option 2, Srinagar, is incorrect as the counter-insurgency school is not situated in Srinagar. Srinagar is the largest city in the Kashmir Valley, but it is not the location of the counter-insurgency school.
Option 3, Tezpur, is also not the correct answer. Tezpur is a town in the state of Assam in India, but it is not the location of the counter-insurgency school.
Therefore, the correct answer is Vairengte, option 4. The counter-insurgency school of the Indian Army is situated in Vairengte.